Game is lagging a lot

Hi
So I tried running the OmegaUpdater, it downloaded something. I then proceeded to click on Online, which after a couple of seconds didn’t work (“Disconnected from server”)
Tried couple of times, restarted pc, same results.
Then I uninstalled the game again, downloaded the file again (OmegaInstaller.exe), and installed it again. I disabled my Antivirus which is Windows defender currently. Ran the installation file as administrator, and when the installation finished I ran the YGO Omega.exe, administrator as well.
Message saying there is an update available popped up, downloaded it, and then I proceeded to test it when everything finished. Now it’s the same as before (it takes a lot of time to load every action). Antivirus is still disabled. I close the game and try running the OmegaUpdater.exe again, as administrator. Same results.
So I’m still where i started.
I have to say tho, my brother’s game is now working fine, which makes me think something is wrong with my account?
What can I do?
Thank you for your time and help.

P.S: I have to say that it doesn’t need to be an online game to be so slow. Everytime I try it is in “Testing hand mode”, in which case is still really slow. I’ve tried online games and with my brother as well, they don’t work either.